Sponge: Set up Cornell Notes on pg. 37 Topic: 4.2 Food Chains and Webs Essential Question: Draw...

Sponge: Set up Cornell Notes on pg. 37

Topic: 4.2 Food Chains and Webs

Essential Question: Draw three food chains, each with at least 3 linkages (4 organisms)-words only

BIOZONE: P. 168-171,174

4.2 Food Chains and webs

EQ: Draw three food chains, each with at least 3 linkages- words only

Key Vocabulary:Food ChainsFood WebsTrophic Levels:

Primary/Secondary/Tertiary/Quaternary ConsumerText: P. 752-753

Get out homework for signature(Monday’s and Tuesday’s)

P. 36 Trophic Level Pyramid

Build-Your-Own Food Web

In class: Construct a food web

Understanding

• Most ecosystems rely on a supply of energy from sunlight

The Importance of Sunlight• All life you see around you on Earth’s surface relies either

directly or indirectly on sunlight

Understanding

• Light energy is converted to chemical energy in carbon compounds by photosynthesis

The role of photosynthesisRemember photosynthesis: • Takes simple inorganic CO₂ and convert it into energy-rich

sugar C₆H₁₂O₆• Light energy from sun is being converted into chemical energy

(food)

The role of photosynthesis• Chemical energy refers to the fact that organic compounds

such as carbs, proteins, and lipids are rich in energy – Can be measured by calories or kilocalories– One way to release the chemical energy from organic compounds is

to digest the food

Understanding

• Chemical energy in carbon compounds flows through food chains by means of feeding

Food Chains• By feeding on producers, consumers can utilize the chemical

energy to grow and stay healthy

• A food chain is a model that shows a sequence of feeding relationships and energy flow between species • A food chain follows the connection between one producer and a single

chain of consumers within an ecosystem.

DESERT COTTONTAILGRAMA GRASS HARRIS’S HAWK

Food Chains

*The direction of the arrow shows the direction of energy flow

Trophic levels refer to an organism’s position in a food chain.• Classify organisms by their feeding relationships with the other organisms in

the same ecosystem

T5= Quaternary Consumer

T4= Tertiary Consumer

T3= Secondary Consumers

T2= Primary Consumers herbivores

T1= Primary Producers plants

……

C a

r n

i v

o r

e s

……

.

Draw on top of P. 36- include examples

Understanding

• Most species occupy different trophic levels in multiple food chains

Organisms can fit into more than one tropic level!

• Ex: A common seal is in T3 when it feeds on Grey Mullet• But will be in T4 when it feeds on lobster

T1

T2

T3

T1

T2

T3

T4

Understanding

• A food web shows all the possible food chains in a community

• A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.• An interconnecting series of food chains.• Since organisms usually eat more than one type of food, a simple food chain does

not tell the whole story

ENERGY

Arctic Marine Food Web

Food Webs 3m7s

• https://www.youtube.com/watch?v=MGODmyXkkPU

Understanding

• Energy losses between trophic levels restrict the length of food chains and the biomass of higher trophic levels

Energy Levels in Trophic levels• The number of levels is limited by how much energy enters the

ecosystem– Energy is lost at each level• So the # of organisms in the chain as well as the quantity of light available at

the beginning will determine how long the chain is

Determining an organism’s tropic level

In order to determine the tropic level of each organism start with the producer.• Remember: some organisms occupy more than one trophic level or

take their food from multiple trophic levels

Algae mosquito larva dragonfly larva fish raccoon

Algae (T1) mosquito larva (T2) dragonfly larva (T3) fish (T4)raccoon (T5)

In Class Practice: Construct a Food Web

• Algae (plant) is eaten by the mayfly larva• Leaf debris is eaten by the caddis fly larva and the

blackfly larva• The mayfly larva, caddis fly larva, and the blackfly

larva are eaten by juvenile trout (fish)• The juvenile trout is eaten by the kingfisher (bird)• The mayfly larva is also eaten by the sculpin (fish) and

the stonefly larva, all of which are eaten by adult troutPlease include labels to indicate the tropic level of

each organism (T 1-5)

Middle of p. 36

Just use words and

arrows

T3/

On the bottom p. 36: Construct a food web containing up to 10 organisms• All trophic levels must be labeled (T1/T2 etc.)

• Remember: some organisms occupy more than one trophic level or take their food from multiple trophic levels

•Must have pictures